You might think, “But I saw a documentary about ancient water trapped in ice for thousands of years!” True! But that water was sealed in a natural vault, not a $0.50 plastic bottle from a gas station. Your bottle is porous. Over time, air sneaks in. Oxygen changes the taste. Flat, stale water is a real thing.
How Long Can You Keep Water In Plastic Bottles at Albert Hoopes blog
Even worse: If you see green or brown slime floating in your bottle? That’s algae. Yes, algae can grow in bottled water if it gets sunlight. You’ve created a tiny pond. A sad, slimy pond.
Quirky fact: In 2016, a 100-year-old bottle of Perrier was found in a shipwreck. Divers opened it. The water was still carbonated. But that water was glass-sealed, not plastic. Glass is the king. Plastic is the court jester.
